Firewall & CDN: Errors & Solutions

SiteLock has a very specific error page that gives some troubleshooting information as well as an Error Code, which can be matched with the error codes below to find a solution to the problem.

Please Note: While all errors will have SiteLock branding, the underlying cause may require web host or web developer intervention. If you have any questions about what the error means, please don't hesitate to reach out to SiteLock Support for more information. However, please be aware that SiteLock Support may not be able to resolve the issue. For example, Error Code 20 typically means the hosting server is not accessible for some reason. Rather than display true errors or the stack trace of the issue, which an attacker could use to take advantage of a temporary outage, a SiteLock-branded error is returned instead.

Error Code: 8

• Description: The proxy failed to connect to the web server, due to TCP connection rejection (TCP Reset).
• Details: This means that the SiteLock firewall is unable to communicate with the hosting server where the website exists.
• Solution: Confirm "Site IP" is correct in Firewall Settings, Whitelist Firewall IPs on Hosting Server.

Error Code: 15

• Description: The request was blocked by our security service.
• Details: The request was blocked based on your Firewall settings (Block Request, Block User, or Block IP).
• Solution: Review settings under Firewall -> Proactive Settings for the above settings. If everything looks good, whitelist the IP (see: whitelist article).

Error Code: 16

• Description: The request was blocked by our security service.
• Details: The request was blocked based on your Firewall settings (Bot Access Control or Block Specific Sources).
• Solution: Review settings under Firewall -> Responsive Settings for the above settings. If everything looks good, whitelist the IP (see: whitelist article).

Error Code: 17

• Description: The request was blocked by our security service.
• Details: The request was blocked based on your Firewall settings (Block User by Country).
• Solution: Review settings under Firewall -> Proactive Settings for the above settings. If everything looks good, whitelist the IP (see: whitelist article).

Error Code: 20

• Description: The proxy failed to connect to the web server, due to TCP connection timeout.
• Details: This either means your hosting server is down, or the Firewall is pointing to the wrong Site IP in (Firewall -> General Settings -> Site IP Address).
• Solution: Check the "Site IP Address" listed in the above path. If this is incorrect, update it and wait about 15 minutes for changes to take effect. If this is correct, reach out to your host to investigate any server outages.
  • Note: When you reach out to hosting support about this issue, you may be advised to contact SiteLock for troubleshooting due to the domain pointing to the SiteLock Firewall DNS. This error code does not suggest an error between the site visitor and the firewall. This suggests an error between the firewall and the hosting server, and the hosting server is what we're asking hosting support to troubleshoot. In some cases, it may be advisable to disable the firewall by pointing the domain directly to the hosting server so that the host can troubleshoot. This would direct the domain to the hosting IP without involving SiteLock, so the host can troubleshoot the issue directly. More advanced users can also modify their hosts file to point the domain to the hosting server without modifying DNS and waiting for changes. This should be done with extreme caution.

Error Code: 22

• Description: The proxy failed to resolve site from host name, if this site was recently added please allow a few minutes before trying again.
• Details: Services expired or were cancelled before the domain was pointed away from SiteLock DNS.
• Solution: Update the domain's A-Record and "www" CNAME to point to the hosting IP. Wait about 1-4 hours for propagation to take effect.

Error Code: 23

• Description: The proxy failed to resolve site from host name - duplicate sites with same host name exist. To resolve this issue, complete the DNS changes as instructed
• Details: This means your domain may already have existing/duplicate SiteLock services.
• Solution: Contact SiteLock support so we can investigate and identify duplicate accounts.

Error Code: 26

• Description: SSL is not supported
• Details: There is an issue with your firewall and SSL configuration.
• Solution: Confirm that your SSL has been properly installed on the hosting server (may require hosting support assistance) as well as being installed in the SiteLock Firewall (may require SiteLock support assistance).

More Information: https://docs.imperva.com/bundle/cloud-application-security/page/error-codes.htm